A Visual Experimental Device and Method for Mine Stability under Cyclic Hydrogen Storage and Release Conditions

Abstract

This invention discloses a visualization test device and method for mine stability under cyclic hydrogen storage and release conditions, belonging to the field of engineering testing technology. The test device includes two interconnected main bodies. The first main body contains an axial pressure chamber and a piston-type axial pressure head. The second main body is detachably connected to the first main body and contains a sample placement chamber and a pressure chamber. The axial pressure head enters the sample placement chamber to apply pressure to the sample. The pressure chamber is sealed by the sample, forming a closed space. The pressure chamber is connected to an inlet pipe and an outlet pipe, and is replenished with gas through a high-pressure gas source. The internal gas is discharged into a gas storage cylinder by a vacuum pump, and the gas flow is controlled by valves, pressure gauges, etc. on the pipeline. The gas storage cylinder is connected to a gas chromatograph for analysis. The device of this invention has a simple structure, is easy to operate, can improve testing accuracy, and can simulate various working conditions. At the same time, the device can accurately control and monitor parameters such as pressure, flow rate, and temperature, ensuring the safety of the experiment and the stability of the hydrogen storage process.

Description

Technical Field

[0001] This invention relates to the field of engineering testing technology, and in particular to a visualization test device and method for mine stability under cyclic hydrogen storage and release conditions. Background Technology

[0002] With the transformation of the global energy structure and the rapid development of clean energy, gas storage technology has become crucial for achieving efficient energy utilization and sustainable development. Hydrogen energy, as a low-carbon new energy source, is considered a key carrier for energy transition. Hydrogen storage, as a novel energy storage method, boasts advantages such as long discharge time, large capacity, high economic efficiency, and environmental friendliness, making it significant for achieving the goals of "carbon peaking and carbon neutrality." As important energy reserve facilities, the safety and stability of hydrogen storage facilities during construction and operation have received widespread attention.

[0003] Abandoned mine shafts, as potential hydrogen storage resources, have attracted much attention due to their large storage capacity and good safety. However, the stability of the surrounding rock is a key factor determining whether a mine shaft can be safely utilized. Currently, existing testing methods have significant uncertainties in assessing surrounding rock stability, and the rationality of their design and performance directly affect the accuracy and practicality of the research results. Furthermore, existing experimental devices generally suffer from complex structures, cumbersome operation, and insufficient testing accuracy, making it difficult to meet the growing demands of scientific research and engineering. Summary of the Invention

[0004] The purpose of this invention is to provide a simple, easy-to-operate, and highly accurate experimental device and method for visualizing mine stability under cyclic hydrogen storage and release conditions, which can simulate various working conditions, to meet the growing scientific research and engineering needs.

[0005] To achieve the above objectives, on the one hand, the present invention provides a visualization test device for mine stability under cyclic hydrogen storage and release conditions, comprising:

[0006] The first device body has a hollow interior forming an axial pressure chamber. An axial pressure head reciprocates within the axial pressure chamber in a piston-like manner. The bottom of the axial pressure chamber has a downward pressure port to accommodate the sliding out of the axial pressure head.

[0007] The second device body is detachably connected to the first device body. The second device body has a sample placement chamber that is connected to the lower pressure port. The sample placement chamber is used to place the sample and allow the axial pressure head to be pressed in. A pressure chamber is sunken at the bottom of the sample placement chamber. An annular step is formed at the top of the pressure chamber. After the sample is placed in, it forms a sealed contact with the annular step, sealing the bottom pressure chamber into a closed space.

[0008] The axial pressure head enters from the inlet of the sample placement chamber and applies downward pressure to the sample.

[0009] The pressure chamber is connected to a high-pressure gas source and a gas flow pump via an inlet pipe, and the pressure chamber is connected to a vacuum pump and a gas storage cylinder via an outlet pipe. Both the inlet and outlet pipes are equipped with valves, pressure gauges, thermometers, and flow meters. The gas storage cylinder is connected to a gas chromatograph.

[0010] In some alternative implementations, the axial pressure head includes a lower pressure section, a piston section, and a shaft section. The piston section is in piston-like sliding engagement with the inner wall of the axial pressure chamber. The lower pressure section is located at the center of the bottom of the piston section, and its outer diameter is smaller than that of the piston section and is adapted to the inner diameter of the sampling chamber. The shaft section is located above the piston section and passes through and guides the sliding motion on the top of the first device body.

[0011] In some alternative implementations, the piston section divides the axial pressure chamber into an upper chamber and a lower chamber; the upper chamber is connected to an oil blowing line and an inlet / outlet oil line, the oil blowing line is connected to an air pump, and the inlet / outlet oil line is connected to an oil pump, an oil tank, and a liquid flow pump; the lower chamber is connected to an exhaust line, and an air compression conversion switch is installed on the exhaust line.

[0012] In some alternative implementations, the mine stability visualization test apparatus under cyclic hydrogen storage and release conditions also includes a control system, wherein the liquid flow pump, the gas flow pump, and the gas chromatograph are all electrically connected to the control system.

[0013] In some alternative implementations, the shaft segment of the axial indenter is equipped with an axial displacement sensor.

[0014] In some alternative implementations, the annular step is provided with an annular groove, and a sealing ring is provided in the annular groove.

[0015] In some alternative implementations, at least one side of the sample placement chamber is made of a transparent material to facilitate observation of changes in the sample during the test.

[0016] In some alternative implementations, an electric heating ring is provided on the inner wall of the pressure chamber, and a temperature thermocouple is also provided inside the pressure chamber.

[0017] In some alternative implementations, the first device body and the second device body are fastened together by bolts.

[0018] The above structure aims to provide a visual experimental device for the deformation mechanism of a multi-layered composite structure in an abandoned mine under cyclic hydrogen storage and release conditions. It is mainly used to study and test the stability of the surrounding rock when the abandoned mine is used as a hydrogen storage tank. Pressure-resistant oil is injected into the axial pressure chamber through the oil tank, and the hydraulic pump is controlled by the control system to apply axial pressure. At the same time, a gas pressure chamber is set below the sample. Gas is injected into the gas pressure chamber through a high-pressure gas source, and the gas compressor is controlled by the control system to apply gas pressure.

[0019] On the other hand, the present invention provides a method for visualizing mine stability under cyclic hydrogen storage and release conditions, using the mine stability visualization test device under cyclic hydrogen storage and release conditions described in any of the above claims. The method includes the following steps:

[0020] Step S1: Place the sample in the sample placement chamber of the second device body, and ensure that the bottom of the sample contacts the sealing ring to form a seal, so that the pressure chamber is in a closed state.

[0021] Step S2: Connect the first device body and the second device body housing, and ensure a seal;

[0022] Step S3: Apply axial load to the sample by controlling the axial indenter through the control system;

[0023] Step S4: Inject gas into the pressure chamber and apply gas pressure, while monitoring the gas flow rate, pressure, and temperature;

[0024] Step S5: After the test, remove the gas and axial pressure, collect the gas and analyze its purity and composition, return the hydraulic oil to the oil tank, turn off the air compression switch, and take out and store the sample.

[0025] Step S6: Record the experimental data and derive the experimental results based on the experimental data.

[0026] The present invention has the following technical effects:

[0027] The mine stability visualization test device under cyclic hydrogen storage and release conditions of this invention has a simple structure and is easy to operate. It can improve testing accuracy, simulate various operating conditions, and visualize the test process. This device can accurately control and monitor parameters such as pressure, flow rate, and temperature, ensuring the safety of the test and the stability of the hydrogen storage process. The test device and method of this invention support the storage and utilization of hydrogen energy, help improve the utilization rate of abandoned mine resources, promote energy transition and environmental protection, meet scientific research and engineering needs, and provide a scientific basis for the design and stability study of hydrogen storage facilities in abandoned mines. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 This is a schematic diagram of a mine stability visualization test device under cyclic hydrogen storage and release conditions according to the present invention.

[0030] In the diagram: 1. Axial pressure chamber; 2. Axial pressure head; 3. Flange; 4. Air compression conversion switch; 5. Axial displacement sensor; 6. Oil blowing pipeline; 7. Air pump; 8. Inlet / outlet oil pipeline; 9. Oil tank; 10. Liquid flow pump; 11. Control system; 12. Annular groove; 13. Sealing ring; 14. Bolt; 15. Sample; 16. High-strength transparent glass plate; 17. Annular step; 18. Removable wire mesh; 19. Pressure chamber; 20. Inlet pipeline; 21. High-pressure air source; 22. Gas flow pump; 23. Temperature thermocouple; 24. Electric heating ring; 25. Outlet pipeline; 26. Vacuum pump; 27. Gas storage cylinder; 28. Gas chromatograph; 29. ​​Needle valve; 30. Ball valve; 31. Pressure gauge; 32. Temperature gauge; 33. Flow meter. Detailed Implementation

[0031] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] Currently, existing technologies involve converting abandoned mine shafts into hydrogen storage facilities to improve the utilization rate of abandoned mine resources and ensure the safe and stable storage of hydrogen. This structure includes an initial support layer, drainage structure, impermeable concrete layer, steel lining, and sealing device. The steel lining is a double-layer sandwich structure, consisting of an outer steel lining, an inner steel lining, and a UHPC concrete filling layer between the two steel linings. This design aims to utilize the stable environmental factors of the mine shaft to achieve safe storage and improve the structural safety of the hydrogen storage facility.

[0033] Current research progress includes the optimization of underground hydrogen storage, the determination of interfacial tension between rocks and fluids, and the comprehensive characterization of the wettability and interfacial tension of the hydrogen-saltwater-quartz system. These studies provide a scientific basis for the design of multi-layered composite structures and the understanding of deformation mechanisms in abandoned mine hydrogen storage facilities. Some studies have combined numerical simulation, laboratory experiments, and theoretical analysis to investigate the damage evolution characteristics of rocks under cyclic loading and unloading, the seepage-damage-stress coupled mechanical model, and the stability mechanism of gas-bearing surrounding rocks under injection-production cycles.

[0034] In summary, a visualization test device for the deformation mechanism of multi-layered composite structures in abandoned mine shafts under cyclic hydrogen storage and release conditions is under active research and development. This invention aims to provide a visualization test device and method for mine shaft stability under cyclic hydrogen storage and release conditions, in order to help study and understand the deformation mechanism of abandoned mine shafts under hydrogen storage and release conditions, and ensure the safety and stability of the hydrogen storage process.

[0035] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0036] Reference Figure 1As shown, this embodiment of the invention provides a visualization test device for mine stability under cyclic hydrogen storage and release conditions, including a first device body and a second device body that are sealed and connected at the top and bottom. The housings of the first device body and the second device body are detachably connected. The interior of the first device body is hollow and forms an axial pressure chamber 1. An axial pressure head 2 is installed in the axial pressure chamber 1 in a piston-like manner. The bottom of the first device body has a downward pressure port, the size of which is consistent with the size of the upper opening of the housing of the second device body and is adapted to the outer diameter of the downward pressure section of the axial pressure head 2. The axial pressure head 2 enters the housing of the second device body through the downward pressure port of the first device body so as to apply downward pressure to the sample 15 placed in the housing of the second device body. The axial indenter 2 includes a pressing section close to and facing the sample 15, a piston section above the pressing section, and a shaft section above the piston section. The shaft section passes through and slides at the top center of the first device body. The piston section has an outer diameter that matches the inner diameter of the axial pressure chamber 1, and the two form a piston-type sliding fit. The inner diameter of the pressing section is smaller than that of the piston section and is close to the inner cavity (sample placement chamber) of the second device body housing at the bottom, so that it can reciprocate between the axial pressure chamber 1 and the sample placement chamber in a piston-like manner. The second device body is a shell structure with an open top and a T-shaped chamber inside. At least one side of the shell body of the second device body is made of transparent material to facilitate observation of the internal situation. The T-shaped chamber includes a sample placement chamber at the top and a pressure chamber 19 at the bottom. The sample placement chamber is used to hold the sample 15. The sample 15 can be supported on the annular step 17 above the pressure chamber 19. After the sample 15 is placed, the pressure chamber 19 at the bottom forms a sealed space. The pressure of the pressure chamber 19 can be adjusted by injecting or extracting gas to achieve the corresponding test purpose.

[0037] Specifically, in the above embodiment, the top center of the first device body has an opening and a flange 3 is installed. The shaft section of the axial pressure head 2 cooperates with the flange 3 to form a sealed sliding connection. Under the action of the driving mechanism, the shaft section drives the piston section and the lower pressure section to reciprocate up and down. The piston section slides in contact with the inner wall of the axial pressure chamber 1, and a sealing ring 13 embedded in the inner wall of the axial pressure chamber 1 is provided to achieve a sealed sliding connection. The piston section divides the axial pressure chamber 1 into an upper chamber and a lower chamber. The upper chamber is connected to the oil blowing pipeline 6 and the inlet / outlet oil pipeline 8. The oil blowing pipeline 6 is connected to the air pump 7 and is equipped with a pressure gauge 31 and a valve. The inlet / outlet oil pipeline 8 is connected to the oil pump, the oil tank 9 and the liquid flow pump 10, and is equipped with a pressure gauge 31 and a valve. The oil pump, acting as the driving mechanism for the axial pressure head 2, delivers hydraulic oil from the oil tank 9 to the axial pressure chamber 1 via the inlet / outlet oil lines 8, thereby generating downward hydraulic pressure on the axial pressure head 2 to drive it downwards. The air pump 7 blows air into the axial pressure chamber 1 via the oil blowing line 6, thus returning the hydraulic oil in the axial pressure chamber 1 to the oil tank 9 via the inlet / outlet oil lines 8. The lower chamber is connected to an exhaust line, on which an air compression switch 4 is installed. During the axial pressure loading phase, this air compression switch 4 needs to be turned on to promptly discharge the gas in the lower section of the axial pressure chamber 1 during the downward movement of the axial pressure head 2, ensuring its smooth downward movement.

[0038] In some embodiments, the first device body and the second device body housing are fastened together by bolts 14, and a sealing ring 13 is placed at the connection position. Specifically, an annular groove 12 is opened on the cross-section where the first device body and the second device body housing are connected, and a sealing ring 13 is placed in the annular groove 12, so that the first device body and the second device body housing can be detachably and sealed, which is convenient for inserting the sample 15 and ensures the sealing of the connection between the two.

[0039] It should be understood that in practical applications, the first device body and the second device body housing can also adopt other detachable fastening connection methods, such as snap-fit, fastener snap-fit, etc., but the firmness and tightness of the connection between the two must be ensured.

[0040] In some embodiments, the inner wall of the axial pressure chamber 1 is also provided with a groove for placing the sealing ring 13, and the inner circumferential surface of the bottom outlet of the axial pressure chamber 1 is also provided with a groove for placing the sealing ring 13, so that after the sealing ring 13 is placed, it can be basically in the same vertical plane as the inner wall, thereby achieving a good sealing effect without affecting the piston movement of the axial pressure head 2.

[0041] In this embodiment, the pressure chamber 19 at the bottom of the second device housing is connected to a high-pressure gas source 21 via an inlet pipe 20, and a valve, pressure gauge 31, temperature gauge 32, and flow meter 33 are installed on the inlet pipe 20. The pressure chamber 19 is connected to a vacuum pump 26 and a gas storage cylinder 27 via an outlet pipe 25, and a ball valve 30, pressure gauge 31, temperature gauge 32, and flow meter 33 are installed on the outlet pipe 25. The gas storage cylinder 27 is connected to a gas chromatograph 28. During the experiment, the changes in gas pressure, temperature, and flow rate can be visually perceived by observing the pressure gauge 31, temperature gauge 32, and flow meter 33.

[0042] In some embodiments, a control system 11 is also included, to which the gas chromatograph 28 is electrically connected. The control system 11 is also electrically connected to the liquid flow pump 10 and the gas flow pump 22.

[0043] In some embodiments, an axial displacement sensor 5 is provided on the shaft segment of the axial pressure head 2.

[0044] In some embodiments, the valves on the inlet pipe 20 and the outlet pipe 25 are ball valves 30, and the valve near the gas storage cylinder 27 is a needle valve 29.

[0045] In some embodiments, the annular step 17 is provided with an annular groove 12 for placing the sealing ring 13. When the sample 15 is placed on the annular step 17, it is pressed against the sealing ring 13 to form a seal, ensuring that the air pressure chamber 19 at the bottom forms a closed space.

[0046] In some embodiments, depending on the needs of the experiment, a removable wire mesh 18 may be placed on the annular step 17. The main function of the removable wire mesh 18 is to prevent the sample 15 from peeling off due to damage and falling into the bottom of the pressure chamber 19.

[0047] In some embodiments, an electric heating ring 24 is installed on the inner wall of the pressure chamber 19, which can heat the gas.

[0048] In some embodiments, a temperature thermocouple 23 is also provided in the pressure chamber 19. The temperature change of the air pressure can be directly perceived through the temperature gauge 32, and the temperature thermocouple 23 can further accurately perceive the temperature change of the gas in the pressure chamber 19.

[0049] In some embodiments, the housing of the second device body can be made of high-strength transparent glass. It can be an integrally formed high-strength transparent glass housing, or high-strength transparent glass can be installed on one side of the housing of the second device body (the observation side directly in front of the sample 15) to achieve visualization of the test process.

[0050] This invention also provides a method for visualizing mine stability under cyclic hydrogen storage and release conditions, using the mine stability visualization test device under cyclic hydrogen storage and release conditions described in the above embodiments. The test method includes the following steps:

[0051] Step S1, Preparation stage: Open the first device body and the second device body, place the sealing ring 13 on the annular step 17 at the bottom of the sample chamber, place the sample 15 in the sample chamber of the second device body, and make full contact between the bottom of the sample 15 and the sealing ring 13 to form a seal. At this time, the air pressure chamber 19 at the bottom of the sample 15 is in a closed state.

[0052] Step S2, Connection Stage: The first device body and the second device body housing are sealed and connected. Specifically, a sealing ring 13 is placed in the annular groove 12 on the lower end face of the first device body, and then the first device body and the second device body housing are fastened together by bolts 14 along the periphery of the two devices.

[0053] Step S3, Axial pressure loading: First, turn on the air compression conversion switch 4, then inject hydraulic oil into the sealed space above the axial pressure chamber 1 through the oil tank 9 and the inlet / outlet oil line 8, drive the axial pressure head 2 to move downward, and finally control the liquid flow pump 10 through the control system 11 to apply axial load to the sample 15.

[0054] Step S4, Gas Pressure Loading: First, the gas pressure chamber 19 is evacuated to a vacuum state using the vacuum pump 26 and the outlet pipe 25. Then, gas is injected into the gas pressure chamber 19 through the high-pressure gas source 21 and the inlet pipe 20. Finally, the gas flow pump 22 is controlled by the control system 11 to apply gas pressure to the sample 15. At the same time, the changes in gas pressure and flow rate are visually perceived by observing the pressure gauge 31 and the flow meter 33 to complete the test process.

[0055] In some embodiments, step S4 further includes: heating the gas through the electric heating ring 24 while applying gas pressure, and visually sensing the gas temperature through the temperature gauge 32.

[0056] In some embodiments, the temperature change of the gas in the pressure chamber 19 is further accurately obtained by using a temperature thermocouple 23 disposed in the pressure chamber 19.

[0057] Step S5, End Stage: First, the gas flow pump 22 is controlled by the control system 11 to release the gas pressure. Then, the gas is collected through the gas outlet pipe 25 and the gas storage bottle 27. The gas storage bottle 27 is connected to a gas chromatograph 28 to detect the gas purity and analyze the gas components. After that, the liquid flow pump 10 is controlled by the control system 11 to release the axial pressure. Finally, the hydraulic oil in the axial pressure chamber 1 is returned to the oil tank 9 through the inlet / outlet oil pipe 8 via the air pump 7 and the oil blowing pipe 6. The air compression conversion switch 4 is turned off. Then, the bolt 14 is opened, the sample 15 is taken out and numbered for storage.

[0058] Step S6: Data processing: Record the experimental data and derive the experimental results based on the data.

[0059] The visualization test device and method for mine stability under cyclic hydrogen storage and release conditions disclosed in this invention have at least the following beneficial effects compared to the prior art:

[0060] 1. The experimental device of the present invention has a simple structure, is easy to operate, and is easy to assemble and operate, making the experimental process more efficient.

[0061] 2. This invention has higher testing accuracy. Through a precise control system and sensors, such as an axial displacement sensor, it can accurately control and monitor parameters such as pressure, flow rate, and temperature during the test, thereby improving the accuracy of the test results.

[0062] 3. The device of the present invention can simulate various working conditions and realize the simulation of the stability of the mine under different hydrogen storage and release conditions, including the application of axial pressure and gas pressure, as well as the control of temperature and gas composition, providing a diverse experimental environment for research.

[0063] 4. The device of the present invention has a visualized test process. At least one side of the sample placement chamber is made of transparent material, which makes it easy to observe the changes of the sample during the test and enhances the intuitiveness of the test.

[0064] 5. The device of the present invention has higher safety and stability. By precisely controlling the pressure of the gas and liquid, and monitoring the temperature and gas composition, the safety of the test process and the stability of the hydrogen storage process are ensured.

[0065] 6. The device of this invention can meet the growing scientific research and engineering needs, especially in the research on the safety and stability of abandoned mine tunnels as hydrogen storage reservoirs. By studying and testing the stability of the surrounding rock when abandoned mine tunnels are used as hydrogen storage reservoirs, it helps to improve the utilization rate of abandoned mine resources and ensure the safety and stability of hydrogen storage. It also provides a scientific basis for the design of multi-layer composite structures and the understanding of deformation mechanisms of hydrogen storage reservoirs in abandoned mine tunnels.

[0066] All aspects not detailed in this invention are conventional technical means well known to those skilled in the art.

[0067] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0068] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A visualization test device for mine stability under cyclic hydrogen storage and release conditions, characterized in that, include: The first device body has a hollow interior forming an axial pressure chamber (1). An axial pressure head (2) reciprocates within the axial pressure chamber (1) in a piston-like manner. The bottom of the axial pressure chamber (1) has a downward pressure port to accommodate the sliding out of the axial pressure head (2). The second device body is detachably connected to the first device body. The second device body has a sample placement chamber that is connected to the lower pressure port. The sample placement chamber is used to place the sample (15) and allow the axial pressure head (2) to be pressed in. A pressure chamber (19) is sunken at the bottom of the sample placement chamber. An annular step (17) is formed at the top of the pressure chamber (19). After the sample (15) is placed in, it forms a sealed contact with the annular step (17), sealing the pressure chamber (19) at the bottom into a closed space. The axial pressure head (2) enters from the inlet of the sample chamber and applies downward pressure to the sample (15); the axial pressure head (2) includes a lower pressure section, a piston section and a shaft section. The piston section is in piston-like sliding fit with the inner wall of the axial pressure chamber (1). The lower pressure section is located at the center of the bottom of the piston section. Its outer diameter is smaller than that of the piston section and is adapted to the inner diameter of the sample chamber. The shaft section is located above the piston section. The shaft section passes through and guides the sliding motion on the top of the first device body; the piston section divides the axial pressure chamber (1) into an upper chamber and a lower chamber; the upper chamber is connected to an oil blowing pipe (6) and an inlet / outlet oil pipe (8). The oil blowing pipe (6) is connected to an air pump (7). The inlet / outlet oil pipe (8) is connected to an oil pump, an oil tank (9) and a liquid flow pump (10); the lower chamber is connected to an exhaust pipe. An air compression conversion switch (4) is installed on the exhaust pipe. The pressure chamber (19) is connected to a high-pressure gas source (21) and a gas flow pump (22) through an inlet pipe (20). The pressure chamber (19) is connected to a vacuum pump (26) and a gas storage cylinder (27) through an outlet pipe (25). Both the inlet pipe (20) and the outlet pipe (25) are equipped with valves, pressure gauges (31), thermometers (32) and flow meters (33). The gas storage cylinder (27) is connected to a gas chromatograph (28). The control system (11) is electrically connected to the liquid flow pump (10), the gas flow pump (22) and the gas chromatograph (28).

2. The visualization test device for mine stability under cyclic hydrogen storage and release conditions according to claim 1, characterized in that, The axial displacement sensor (5) is provided on the shaft segment of the axial pressure head (2).

3. The visualization test device for mine stability under cyclic hydrogen storage and release conditions according to claim 1, characterized in that, The annular step (17) is provided with an annular groove (12), and a sealing ring (13) is provided in the annular groove (12).

4. The mine stability visualization test device under cyclic hydrogen storage and release conditions according to claim 1, characterized in that, At least one side of the sample placement chamber is made of transparent material to facilitate observation of the changes in the sample (15) during the test.

5. The visualization test device for mine stability under cyclic hydrogen storage and release conditions according to claim 1, characterized in that, An electric heating ring (24) is provided on the inner wall of the pressure chamber (19), and a temperature thermocouple (23) is also provided in the pressure chamber (19).

6. The visualization test device for mine stability under cyclic hydrogen storage and release conditions according to claim 1, characterized in that, The first device body and the second device body are fastened together by bolts (14).

7. A method for visualizing mine stability under cyclic hydrogen storage and release conditions, using the visualization test apparatus for mine stability under cyclic hydrogen storage and release conditions as described in any one of claims 1 to 6, characterized in that, Includes the following steps: Step S1: Place the sample (15) in the sample placement chamber of the second device body and ensure that the bottom of the sample (15) contacts the sealing ring (13) to form a seal, so that the pressure chamber (19) is in a sealed state. Step S2: Connect the first device body and the second device body housing, and ensure a seal; Step S3: The axial load is applied to the specimen (15) by controlling the axial indenter (2) through the control system (11); Step S4: Inject gas into the pressure chamber (19) and apply gas pressure, while monitoring the gas flow rate, pressure, and temperature; Step S5: After the test, remove the gas and axial pressure, collect the gas and analyze its purity and composition, return the hydraulic oil to the oil tank (9), turn off the air compression switch (4), and take out and store the sample (15). Step S6: Record the experimental data and derive the experimental results based on the experimental data.

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